Linux中用户空间ioctl传递的cmd参数不对。

1.用户空间调用ioctl函数传递cmd参数代码如下

 printf("In the app program the LED_ON is:%d\n",LED_ON);
    printf("In the app program the LED_OFF is:%d\n",LED_OFF);
    sleep(1);
    for (i = 0;i < 3;i++) {
        ioctl(fd,LED_ON);
        sleep(1);
        ioctl(fd,LED_OFF);
        sleep(1);
    }

2.内核空间ioctl解析函数如下

static int char_cdev_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
{
    
    printk(KERN_INFO "cmd is:%d\n",cmd);
    printk(KERN_INFO "LED_ON is:%d\n",LED_ON);
    printk(KERN_INFO "LED_OFF is:%d\n",LED_OFF);

    if (_IOC_TYPE(cmd)!=LED_IOC_MAGIC) {
        return -ENOTTY;
    }
    if (_IOC_NR(cmd) > LED_IOCTL_MAXNR) {
        return -ENOTTY;
    }

    switch(cmd) {
        case LED_ON:
            gpio_set_value(GPIO_LED_PIN_NUM,0);
            printk(KERN_INFO DEVICE_NAME "LED_ON\n");
            break;
        case LED_OFF:
            gpio_set_value(GPIO_LED_PIN_NUM,1);
            printk(KERN_INFO DEVICE_NAME "LED_OFF\n");
            break;
        default:
            gpio_set_value(GPIO_LED_PIN_NUM,1);
            break;
    }
    printk(KERN_INFO DEVICE_NAME " ioctl method!\n");
    return 0;
 }

3.运行结果如下，cmd传递到内核变成了0，但是应用程序中传递的命令是11776和11777，在内核空间打印命令也是11776和11777，唯有cmd的参数不对

[root@EPC-M6G2C driver]# ./driver_test_app
LED_ERR opened!
In the app program the LED_ON is:11776
In the app program the LED_OFF is:11777
cmd is:0
LED_ON is:11776
LED_OFF is:11777
cmd is:0
LED_ON is:11776
LED_OFF is:11777
cmd is:0
LED_ON is:11776
LED_OFF is:11777
cmd is:0
LED_ON is:11776
LED_OFF is:11777
cmd is:0
LED_ON is:11776
LED_OFF is:11777
cmd is:0
LED_ON is:11776
LED_OFF is:11777
Control led end!LED_ERR closed!